Investigating the effectiveness of implementing the science writing heuristic on student performance in general chemistry

This research investigated the effectiveness at how the Science Writing Heuristic in the freshman chemistry laboratory for science and engineering majors at Iowa State University during the fall and spring semesters of the 2002--2003 academic year, was implemented. The Science Writing Heuristic (SWH) consists of two components, writing to learn strategies and conducting the laboratory session in a student-centered, guided-inquiry fashion. The writing component replaced the standard laboratory report with a series of questions that guided the students\u27 critical thinking along the lines of scientific investigation. The writing process helped students construct knowledge. Also critical to the successful implementation of the SWH was conducting the laboratory experiments in a student-centered, guided-inquiry fashion. Through the SWH the students became engaged in meaningful scientific dialogue that promoted knowledge construction. For the SWH to be properly implemented, a classroom dynamic between the teacher and the students should be established. The teacher provides the framework within which the laboratory experiment is conducted and the students respond to that guidance by becoming engaged in the learning process.;Results of the study showed that student scores improved when the teacher properly implemented the SWH, when the students responded positively to the implementation of the SWH, and when there was a proper classroom dynamic created between the teacher and the students. This study revealed that successful implementation of the SWH was beneficial to females and low ability students. This research also demonstrated a connection between the implementation of a learning strategy in the laboratory component of a course and the subsequent benefit in student performance in the lecture component of the course

The effect of simple and complex dual-tasks on ambulation in individuals with Alzheimer's disease and healthy older adults: the role of divided attention and other higher brain functions in gait dual-task performance

Research using gait-dual task methodology suggests that the ability to divide attention during walking appears to be particularly vulnerable to the effects of Alzheimer’s disease (AD), even in the earliest stages of the illness. However, these previous studies are limited by the variability in the types of gait-dual tasks employed, as well as by the inclusion of heterogeneous groups of patients at different stages of disease severity. Study 1 aimed to address these methodological concerns by examining the effects of a simple and complex counting task on gait speed in healthy older adults and individuals with early stage AD. In contrast to previous findings reported in the literature, Study 1 found that when compared to an age appropriate control group individuals with early stage AD were not differentially impaired by a gait dual-task, regardless of the level of task complexity. Study 2 was designed to be a replication and extension of Study 1. In Study 2, sixteen individuals diagnosed with amnestic Mild Cognitive Impairment (aMCI; Petersen, 1999; 2001), 15 individuals with early-stage AD, 17 individuals with moderate stage AD, and 27 healthy older adults performed a timed walking task and simple and complex verbal counting tasks in single and dual-task combinations. In keeping with the results of Study 1, there were no significant differences among the early stage AD group, aMCI group, and healthy older adults on the gait dual-task, regardless of task complexity. However, significant differences were detected between the moderate AD group and the healthy normal control group on the complex dual-task. Study 3 examined the relationship between other higher brain functions and gait speed, with and without interference, in the same group of participants as Study 2. Neuropsychological test scores were used to create theoretically derived cognitive composite scores (i.e., Executive Functioning/Attention/Speed; Episodic Memory; Language) that were used as predictors of gait speed, with and without interference. As expected, The Executive Functioning/Attention/Speed composite was the most potent predictor of gait speed across conditions; however this relationship varied as a function of task complexity and all three factors predicted gait interference in the complex condition, even after controlling for disease severity. In contrast to previous gait dual-task studies, the current research suggests that aMCI and early stage AD are not associated with impaired gait dual-task performance. Rather, these results suggest that when overall degree of dementia severity is controlled for by subdividing patients based on diagnostic criteria, the specific deficit in attention appears later in the progression of AD than previously theorized. Furthermore, these results provide evidence that the relationship between cognition and gait is likely built upon components of cognitive, physical and task prioritization processes that appear to be modulated by task complexity and disease severity

Dairy grazing: heifer development

Original authors: Tony R. Rickard and Stacey A. Hamilton (University of Missouri). Revised 2022 Scott Poock and Stacey Hamilton.stats082022upload"Dairy heifers are the foundation of any dairy enterprise and directly affect future profitability. Because replacement heifers represent a negative cash flow, this aspect of the dairy operation is often neglected. Unfortunately, this neglect often costs producers large amounts of money. The goals of a heifer program should be to achieve the proper size and weight for the particular breed being raised and to calve by 22 to 24 months of age. Missouri data indicate an average age at first calving of 27 to 28 months. The lost net income per heifer is estimated to be at least $1.50 per day for each day over 24 months of age until freshening."--Page 1.Stacey A. Hamilton (Dairy Specialist, Animal Science Department), Scott E. Poock (State Dairy Extension Veterinarian

Cow-Calf Producer Interest in Retained Ownership

The beef industry’s share of domestic meat demand continues to decline, as increasing vertical coordination in pork and poultry contribute to these industries’ ability to offer convenient, consistent, and less expensive products. For such vertical coordination to be effective, incentives must be properly aligned so that those responsible for making the most important investments for system profitability are appropriately compensated. This study demonstrates that cow-calf producers who invest in quality registered cattle and those who are interested in incorporating feedlot and carcass data into herd management decisions are also more interested in retained ownership.beef cattle, property rights theory, retained ownership, Livestock Production/Industries, Marketing, Q13,

Beef Reproductive Technology Adoption- Impact of Production Risk and Capitals

Agriculture, Beef, Artificial insemination, Estrus synchronization, Social capital, Production risk, Technology adoption, Farm Management,

Totalsynthese von Nannocystin Ax sowie Totalsynthese und Strukturrevision von Halioxepin

Im ersten Teil dieser Arbeit wird eine erfolgreiche Totalsynthese von Nannocystin Ax dargestellt. Dieses 21-gliedrige Depsipeptid wurde erstmals 2015 von Hoepfner et al. beschrieben. Zeitgleich wurden von Hoepfner, sowie der Forschungsgruppe von Brönstrup, weitere Vertreter der Nannocystine isoliert. Diese Naturstofffamilie erregte schon kurz nach ihrer Isolation, aufgrund der potenten Cytotoxizität, großes Interesse unter synthetischen Chemikern. Bis heute sind insgesamt sieben verschiedene Totalsynthesen zu den Nannocystinen veröffentlicht worden. In dieser Arbeit wird die zweite Totalsynthese von Nannocystin Ax beschrieben. Als Schlüsselschritt für den Ringschluss diente hierbei eine Macrolactamisierung. Für die Synthese des linearen Vorläufers wurde auf die Polyketid-Peptid-Hybridstruktur des Moleküls zurückgegriffen. So wurde der Polyketidteil zunächst mithilfe einer vinylogen Horner-Wadsworth-Emmons-Olefinierung und einer asymmetrischen vinylogen Mukaiyama-Aldol-Reaktion aufgebaut. In einem ersten Ansatz wurde zunächst der vollständige Peptidteil dargestellt, welcher mit dem Polyketidfragment verknüpft werden sollte. Da dieses jedoch nicht erfolgreich war, wurden die Aminosäurefragmente schließlich schrittweise installiert. Im zweiten Teil dieser Arbeit wird die erfolgreiche Totalsynthese von (−)-Halioxepin beschrieben, sowie dessen tatsächliche Struktur aufgeklärt. Das Meroditerpenoid wurde erstmals 2011 von Tanaka et al. isoliert und charakterisiert. Dabei war die Stereochemie aufgrund von zwei räumlich distanzierten Stereoclustern jedoch nicht eindeutig bestimmbar, sodass zwei potentielle relative Konfigurationen postuliert wurden. 2018 wurde das Molekül von Rodríuguez et al. erneut isoliert. Die Gruppe nutzte DFT-Kalkulationen in Kombination mit NMR-Experimenten, um die wahrscheinlichere der beiden zuvor postulierten Konfigurationen zu ermitteln. Durch eine Totalsynthese beider Diastereomere konnte im Rahmen dieser Arbeit jedoch gezeigt werden, dass es sich bei keiner der vorgeschlagenen Strukturen um den Naturstoff handelt. Eine neue Analyse der NMR-Daten sowie ein Vergleich mit literaturbekannten Verbindungen führten zu dem Vorschlag, die relative Konfiguration zwischen zwei Stereozentren zu invertieren. Die Synthese zweier weiterer Diastereomere mit der invertierten Konfiguration eines Stereozentrums führte dann zur Aufklärung der tatsächlichen relativen Konfiguration von Halioxepin. Die Totalsynthesen aller Diastereomere nutzen asymmetrische katalytische 1,4-Additionen, eine stereoselektive Reduktion eines prochiralen Ketons, eine Iod-vermittelte Cycloetherifizierung sowie eine Aldol-ähnliche Addition, welche durch ein α-chirales Zentrum gesteuert wird, als Schlüsselschritte.In the first part of this thesis, the successful total synthesis of nannocystin Ax is presented. This 21-membered depsipeptide was first described in 2015 by Hoepfner et al. At the same time, the group of Hoepfner and the group of Brönstrup isolated additional members of the nannocystin family. Shortly after their discovery, the nannocystins attracted great attention within the synthetic community due to their potent cytotoxicity. To date, seven total syntheses regarding the nannocystins have been published. In this work, the second total synthesis of nannocystin Ax is described. A macrolactamization was used as a key step and for the synthesis of the linear precursor the hybrid polyketide-peptide structure of the molecule was utilized. The polyketide part was constructed using a vinylogous Horner-Wadsworth-Emmons olefination and an asymmetric vinylogous Mukaiyama aldol reaction. This fragment was initially planned to be coupled to the intact peptide part of the molecule to achieve a convergent approach to the main structure. As connection of both fragments did not work, a stepwise introduction of the amino acid fragments was performed. The second part of this thesis deals with the successful total synthesis of (−)-halioxepine and the structural revision of this molecule. The meroditerpenoid was first isolated in 2011 by Tanaka et al. The structure determination was difficult for Tanaka due to the existence of two separated stereoclusters, so that two possible relative configurations were proposed. In 2018, the group of Rodríguez also isolated halioxepine and used DFT-calculations in combination with NMR-experiments to determine the most probable configuration. In this work, both proposed diastereomers were synthesized and it was shown that none of them fitted the NMR spectra of the natural product. An examination of NMR-data and comparison with literature data led to the suggestion of inverting one of the stereocenters in the cyclohexene-part. The total synthesis of two further diastereomers with this inverted configuration led to one structure whose data fitted those of the natural product. The actual relative and absolute configuration of halioxepine could be identified by this work. The total syntheses of all diasteromers utilized asymmetric catalytic 1,4-additions, a steroselective reduction of a prochiral ketone, an iodine-mediated cycloetherification and an α-sterocenter-directed aldol-type addition of a hydroquinone

Factors involved in the variability of monthly major aircraft accident rates

Results are presented showing the development of regression equations to help determine human and/or aircraft variables which appear to account for the variability in monthly major aircraft accident rates.Naval Safety Center, Norfolk, Virginiahttp://archive.org/details/factorsinvolvedi00poocN6339376P000001N

“Mães, esposas, noivas, irmãs e filhas de mineiros do butiá” e/ou trabalhadoras? Relações de trabalho e gênero na sociedade mineira do RS na década de 1940

O mundo do trabalho se estrutura através de explorações e opressões da classe trabalhadora e, principalmente, do trabalho reprodutivo de mulheres. Esse trabalho foi fundamental para a exploração de carvão no RS, uma vez que a mão de obra não remunerada possibilitou à empresa explorar os trabalhadores e trabalhadoras. Haja vista esse tema, o problema de pesquisa é como possibilitar o ensino de história sobre a generificação do trabalho no cotidiano das minas de carvão através da utilização de fontes em sala de aula? A fonte utilizada para a elaboração do material é a Carta das parentes femininas dos mineiros de Butiá ao Presidente da República, maio de 1946. A escolha por esse documento é devido à agência das mulheres que, apesar de ocuparem o ambiente privado, também estavam a par dos acontecimentos da comunidade mineira, tornando a si próprias protagonistas da história. A partir desse documento, o presente trabalho de conclusão de curso tem como objetivo pensar possibilidades de ensinar história sobre homens e mulheres no cotidiano das minas de carvão através do material didático “Analisando a correspondência: carta das mulheres da região carbonífera de São Jerônimo/RS ao presidente da República na década de 1940”. O resultado é a elaboração do material com intuito de colaborar para a formação social do estudante, através da construção coletiva do conhecimento, debatendo ainda os conceitos de cidadania, de trabalho e de gênero

Percepções de estudantes do Ensino Médio noturno sobre representações de animais em desenhos animados

A humanidade vem se utilizando dos desenhos como meio de comunicação desde seus primórdios e ainda hoje o desenho possui uma importante função na educação. O desenho animado, criado muito antes do cinema, teve um importante marco com a invenção do francês Émile Reynaud, que, no fim do século XIX, criou um sistema de animação com um aparelho, o praxynoscópio, cuja função era projetar as imagens em movimento na parede. Os primeiros desenhos animados eram mudos e sem cores, hoje são animações com efeitos 3D e imagens editadas em computadores. Os filmes de animação podem ser utilizados de diversas formas em sala de aula, incluindo nas aulas de Biologia, pois geralmente contêm informações sobre animais, e este é um dos motivos que guiam este trabalho, analisar a forma que estudantes do ensino noturno de Porto Alegre, RS, veem os desenhos e se relacionam as cenas com as aulas de biologia. Outro ponto a ser pensado e analisado é a percepção do grande público sobre os desenhos que tanto nos entretêm e informam, como recebemos essas informações, o que levamos deles para o nosso dia-a-dia. Como resultados vemos que os estudantes percebem que os desenhos modificam as características dos animais, os quais sofrem uma forte antropomorfização, talvez esta devida ao interesse de torná-los mais aceitáveis por serem parecidos conosco, mais empáticos, aumentando seu sucesso. Porém, a maioria dos estudantes afirma que nunca analisou os desenhos, ratificando a necessidade de termos o professor como um filtro de informações, guiando as análises dentro da sala de aula e colocando alunos mais cientes e críticos em qualquer ambiente que se encontrem, seja ele de concentração ou lazer

Intramammary infections in lactating Jersey cows: Prevalence of microbial organisms and association with milk somatic cell count and persistence of infection.

There is limited data available regarding pathogens causing intramammary infections (IMI) in Jersey cows. The objectives of this study were to characterize the prevalence of IMI caused by different microorganisms in lactating Jersey cattle and evaluate the associations among microbes and somatic cell count (SCC) and persistence of IMI. This prospective, observational, longitudinal study included lactating Jersey cows (n = 753) from 4 farms within a 250-mile radius of Columbia, Missouri. Quarter foremilk samples were aseptically collected monthly for 3 consecutive months. Microorganisms were identified using aerobic milk culture and MALDI-TOF mass spectrometry. A commercial laboratory measured SCC using flow cytometry. Milk culture results were used to classify single microorganism infections as persistent (same microorganism species identified at first sampling and one other sampling) or non-persistent infection. Mixed models were built to evaluate the associations between IMI status and lnSCC as well as persistence and lnSCC. Overall, staphylococci were the most commonly isolated microorganisms among the 7,370 quarter-level milk samples collected. Median prevalence (using all 3 samplings) of specific microbes varied among farms; however, Staphylococcus chromogenes was a common species found at all farms. The most common microbial species that persisted were Staph. chromogenes, Staphylococcus aureus, Staphylococcus simulans, and Streptococcus uberis. Streptococcus dysgalactiae and Staph. aureus were the IMI associated with the most inflammation based on lnSCC. The small number of herds included in this study with the large variation in herd type limits the generalizability of the data. However, results of this study seem to be similar to those of previous studies in other breeds, suggesting management factors are more important than breed-specific differences when evaluating causes of IMI and associated subclinical mastitis